“We are horribly sorry,” the cop said.The 17-year-old girl who was wrongly locked in jail for seven days might be feeling terribly lucky.Amanda Sylvester might still be in jail, facing criminal charges that included aiding and abetting a robbery, were it not for an anonymous tip to a Crimestopper hotline. Her arrest and arraignment stemmed from mistaken identity, according to Lieutenant Rick Ryan of the North Platte Police Department.“Amanda Sylvester was not involved in the robbery,” Ryan said. “We have no information or any reason to believe that Amanda is involved in drugs or any illegal activity. We are horribly sorry about what happened.”A week later, the Crimestopper tip led to the arrest of Kayce Schildhauer, 19, of North Platte.